Disruption of the coracoclavicular ligaments is a common occurrence. In many cases, the injury can be treated conservatively and the only residual problem is that of a mild cosmetic deformity. Several groups of patients, however, do not tolerate the injury well. If the joint is reduced acutely and held reduced during the healing phase, the native ligaments may heal restoring the stability of the joint.
An AC joint repair system using a suture button graft construct formed of oblong button and one round button connected by high strength suture strands and including a graft, i.e., the GraftRope®, is sold by Arthrex, Inc. of Naples, Fla. and disclosed in U.S. Patent Application Publication No. 2010/0125297, incorporated by reference herein. This system requires large 4-6 mm tunnels drilled through the bones (i.e., the clavicle and the coracoid) that pose potential fractures for the clavicle and coracoid. In addition, the four strands of high strength suture or suture tape on the outside of the graft may interfere with the graft incorporation. If the high strength strands attached to the buttons break, device and/or graft fixation is compromised. Further, if the traction suture (which is attached to the oblong button, for pulling the graft through the tunnels) breaks during the pull (due to difficulty of passing the graft though tunnels in the clavicle and coracoid), the graft can get stuck under the clavicle. Friction can also be created on the oblong button (seated against the coracoid) by the two loops of high strength suture traveling in different directions and around the oblong/coracoid button. Securing this oblong/coracoid button can also be difficult.
Another AC joint repair system sold by Arthrex, Inc. is the AC TightRope®, which is disclosed in U.S. Patent Application Publication No. 2007/0179531, the disclosure of which is incorporated by reference herein. The AC TightRope® has a similar suture-button construct as the GraftRope®, but is smaller and does not include a graft. A hole is drilled through the clavicle and the coracoid. The oblong button of the construct is passed through the holes in the clavicle and coracoid until it exits the coracoid base, and the oblong button flips onto the underside of the coracoid. The suture tails of the construct are then tightened to advance the round button down to the surface of the clavicle, and the sutures are tied to stabilize the acromioclavicular (AC) joint. Although the above-described technique and the associated suture button construct works well to stabilize the AC joint, it would be desirable to provide a construct and technique with increased fixation strength.
An improved AC fixation device and technique is needed that provides the superior strength of the GraftRope®, but without the aforementioned disadvantages. The improved technique for AC joint repair would ideally require small holes, a button that contours to the convexity of the bones (i.e., the clavicle and the coracoid), and would include secondary fixation in the clavicle and the subcoracoid to reduce the risk of device loss in case of suture breakage.